Speed control device

ABSTRACT

In a machine where a flexible material is passed consecutively through two sections of a machine, a device for controlling the speed at which the material is passed through one of such sections to correspond with the speed at which the material is passed through the other of these sections. The device includes an impedance element in the form of an arc and a strip beside this element also in arcuate form corresponding to the shape of the element and forming with the side of the element a raceway containing a ball, the arrangement being such that when the impedance element is tilted the ball seeks the lowest position in the raceway to thereby vary the impedance between the strip and one end of the impedance element. Such variation is applied to one of the machine sections to bring the speeds of the section into equalization.

United States Patent [1 1 [111 3,902,645

Keck 1 Sept. 2, 1975 SPEED CONTROL DEVICE Primary ExaminerRichard A. Schacher [76] Inventor: Norman A. Keck, 707 4th Ave., firm-Carl Bail Joliet,Il1. 60433 ABSTRACT 22 Filed: Mar. 28, 1974 [52] US. Cl. 226/44; ZOO/61.45; ZOO/DIG. 29; 226/45; 338/157 [51] Int. Cl. B65 25/04 [58] Field of Search 226/44, 45; 200/61, 45, ZOO/DIG. 29; 338/157, 155

[56] References Cited UNITED STATES PATENTS 1,791,450 2/1931 Kellogg 226/44 X 1,988,192 1/1935 Drabin 338/157 X 2,141,770 12/1938 Solomon 338/157 X 2,492,727 12/1949 Ballard 338/157 X 3,332,060 7/1967 Liljequist 338/157 X In a machine where a flexible material is passed consecutively through two sections of a machine, a device for controlling the speed at which the material is passed through one of such sections to correspond with the speed at which the material is passed through the other of these sections. The device includes an impedance element in the form of an arc and a strip beside this element also in arcuate form corresponding to the shape of the element and forming with the side of the element a raceway containing a ball, the arrangement being such that when the impedance element is tilted the ball seeks the lowest position in the raceway to thereby vary the impedance between the strip and one end of the impedance element. Such variation is applied to one of the machine sections to bring the speeds of the section into equalization.

6 Claims, 4 Drawing Figures SPEED CONTROL DEVICE This application relates to a device for regulating the speed of material being passed through one section of a machine in accordance with the speed of this material in another section of the machine and more particularly to such a device which is sensitive to the depth of the loop formed by the material as it passes from section to section.

BACKGROUND There are many situations in industry where a flexible sheet material such as paper, cloth or the like is passed through different sections of machinery and where the speed at which such material is passed through one of such sections may vary from the speed at which it is passed through another section. It would be highly desirable in such situations to regulate the speed at which the material is passed through the other section to correspond with the speed at which it is passed through the one section so that the material does not either pile up or come into undue tension between the sections.

In speaking of a machine I include the separate mechanisms through which the material is passed continuously, however separated those mechanisms may be.

I am aware of attempts which have been made in the past to solve this problem of variable speed by the provision of devices having levers which contact the loops of material between sections using rheostats arranged to be operated by the levers thus to cause the speed of a driving motor to be increased so as to take up the additional slack when the speed of the material in a previous section is increased. However, an objection to such an arrangement is that the friction involved in Operating the rheostat is too great to be operated by anything which is only in lightly touching contact with the moving loop of material between the sections. Another objection is that the mechanisms needed for the acuation of such rheostats become mechanically complex and cumbersome, requiring special constructions and the use of non-standard electrical parts.

It is therefore an object of this invention to provide a device for coordinating the speed of a material through a section of a machine with the speed at which the material is being passed through another section of the machine and to accomplish this smoothly in an effective way without the use of complicated or complex mechanisms. A further object is to provide such a de vice which will sense the depression of the material between sections with a light touch and which at the same time will positively operate to change the speed of a driving motor for one section so as to coordinate it with the speed of the material being passed through the other sectiomStill another object is to provide such a device which will accomplish the purpose in a smooth manner and in such a way that only small variations in speed will bring on a necessary adjustment. Other objects and advantages of the invention will be apparent as the specification proceeds.

SUMMARY OF THE INVENTION In the device of my invention I provide a tiltable structure on which is mounted an impedance element in the form of an arc. Beside this element is an arcuate strip which forms with the impedance element a raceway containing an electrically conducting ball, and as the tiltable structure is tilted due to an unbalance of speeds, the ball moves in this raceway to vary the impedance between the strips and the end of the impedance element. Such variation in impedance then operates to bring the speeds of the machine sections back into equilization.

DETAILED DESCRIPTION One embodiment of my invention is illustrated in the accompanying drawings in which:

FIG. 1 is a schematic illustration of one type of machine where coordinating of speeds is needed and showing my improved device in a side elevational view;

FIG. 2 is a top view of the improved device illustrated in FIG. 1;

FIG. 3 is a perspective view of the impedance element and conductor strip which provides the raceway for the ball, and

FIG. 4 is a sectional view of the structure as illustrated in FIG. 3.

As illustrated in FIG. 1, there is shown a section 1 of a machine which includes rolls l0 and 11 between which a flexible sheet 12 is passed in the direction of arrows 13. After passing from section 1 the flexible material falls downwardly to form a loop 14, the other side of which passes upwardly and into section 2 of the machine. A motor M drives roll 15 to pass the material onwardly in section 2.

The device for coordinating the speeds of the material in the different sections includes the base 16 on which are mounted bearings 17 and 18 which contain the substantially horizontal shaft 20. Secured to shaft 20 is a member 21 which includes one or more finger pieces 21a extending transversely of the shaft. This member is arranged to contact the lowermost points of the loops so that when moved up and down through contact with the lower part of the loop member 21 this serves to turn shaft 20 clockwise (as seen in FIG. 1) when the loop is deepened, and to turn the shaft counterclockwise as the bottom of the loop raises.

To counterbalance the weight of the member 21 and to press this member into very light contact with the bottom of the loop I provide the counterbalancing arm 22 which is secured to shaft 20 and extends transversely from shaft 20 in a direction opposite to that of member 21. A weight 23 is mounted on arm 22 and is adjustable along the length of the arm as may be necessary to give the slight upward pressure by the member 21 against the bottom of the loop.

The disc 30 is secured to an end of shaft 20. This disc may be circular or any other configuration and serves as a convenient place on which to secure the arcuate impedance element 40 previously referred to. This disc 30 contains apertures through which wires may be passed from one side of the disc to the other.

Referring now more particularly to FIGS. 3 and 4 element 40 is shown to be in arcuate form and has a substantially rectangular cross section. As illustrated, this element is composed of the wire 41 which is wound about the arcuate core 43. One end of the wire is connected to the lead 42. This element 40 is secured by an adhesive or in any suitable way to the insulating disc 44, and disc 44 is secured by bolts 45 to the disc 30.

Besides the element 40 is the strip 50 which also is in arcuate form to correspond with the curvature of element 40. As illustrated, the strip 50 is in the form of a complete ring. It has two or more straps 51 which at their inner ends are secured to the bolts 45 and which serve to hold the strip 50 in spaced position beside element 40, but not in contact with this element. The outer peripheral edge of strip 50 has an inclined lip 52 which serves to retain a ball 53 made of electrically conducting material between the strip and the vertical side 40a of the element 40 (see the lower portion of FIG. 4). The lip 52 forms with side 40a a raceway of V- shaped cross section which holds the ball 53, but allows the ball to move freely within the raceway to seek the lowest position in the raceway. The ball is in contact on its one side with strip 50 and on its other side with a turn of wire 41 on element 40 so as to make an electrical connection between the strip and the wire at each of these points of contact. As the ball moves in its raceway it makes contact with wire 41 at different points along element 40 so as to increase or decrease the resistance of this wire between the ball and the end lead 42.

In the described embodiment the ball and raceway structure is used to increase or decrease the resistance of the element 40 between the lead 42 connected to one end of the element and the lead 54 which is connected through a strap 51 with the strip 50.

Although I prefer, as illustrated, that the arcuate element 40 be mounted on disc 30 with the axis of the element at the center of shaft 20, this element may be mounted at any point on the tiltable structure. Wherever it be mounted on the tiltable structure, it is apparent that tilting of the structure will tilt the arcuate impedance element and cause the balls 53, 55 to move in their raceway. The axis of the arcuate element 40 should not be perpendicular to the axis about which the tiltable structure is tilted, and preferably should be parallel to this axis.

While in the foregoing discussion I have been referring to a direct current system in which there is a variation in resistance between leads 42 and 54 I may also utilize an alternating current system in which the wire coil between the lead at the end of the coil and the point of contact with ball 53 I may also utilize an alternating current system in which the wire coil constitutes an inductance and in which there is variation in inductance as the coil is tilted.

In this disclosure I use the term impedance to represent either a resistance or an inductance or both.

OPERATION We may assume that the impedance element 40 and the strip 50 have been mounted on the disc 30 so that the two ends of the impedance element are near the top and the ball is resting at the bottom of the raceway where it contacts the impedance element near its center when the member 21 is in about its normal position.

When the material 12 speeds up between rolls l and 11 or lags in passing over roll 15 (as shown in FIG. 1) so that the loop 14 deepens, the tiltable structure 21, 20, 3O tilts in a clockwise direction about shaft 20. Since the element 40 is attached to the disc it also tilts so that the ball 53 rolls in its raceway toward the lead 42 thus reducing the impedence between leads 42 and 54. Wires 45, 46 extend from leads 42 and 54 through apertures in disc 30 and about the shaft connecting with the terminals 47, 48; and terminals 47, 48 may be connected to the circuit of motor M so that a reduction in impedance between terminals 47, 48 results in an increase in motor speed, thus to equalize the speed of the two sections of the machine system. This results in raising the loop in material 12 to permit the tiltable structure to return to normal.

Likewise if motor M tends to drive the second section faster than the first section, this will cause the element 40 to be tilted in the opposite direction, thus producing a correction of speeds in the opposite way.

I prefer to use two or more balls in the raceway. As shown in FIG. 3 a second ball 55 lies back of the ball 53. Each of balls 53 and 55 tend to move to the lowest position in the raceway and therefore bear against each other. This produces a damping effect which tends to restrict any tendancy toward oscillation which might occur by reason of the momentum of the balls as they move toward the lowest position.

While I have illustrated only one embodiment of the invention and have described in detail this embodiment with some variations being mentioned, it should be understood that the structure of my invention may be varied in many ways and may be changed in many respects all within the spirit of the invention and within the scope of the appended claims.

I claim:

1. In a machine wherein a flexible material is passed at varying speeds through one section of a machine and also through another section of a machine and wherein said material forms a depending loop of said material between said sections, the improvement in said machine comprising a tiltable structure having a member which is in a position to contact the bottom side of said loop whereby to tilt said structure in one direction when the bottom of said'loop is lowered and in an opposite direction when said bottom is raised, an impedance element in the form of an arc mounted on said tiltable structure, a strip of electrically conducting material beside said element, said strip being in arcuate form corresponding with the arc of said element, said strip being turned inwardly toward said element at its outer edge to form with a side of said element a raceway providing support therein for a ball but being spaced from said side of the element to form an opening through which particles in said raceway may fall from said structure, a ball of electrically conducting material in said raceway, said ball being movable to seek the lowest position in the raceway whereby to change the electrical impedance between said strip and an end of said element when said element is tilted, and being sensitive to changes in said electrical impedance for changing the speed of said material through one of said sections to bring the speed of said material in said sections more nearly into equilibrium.

2. A machine as set forth in claim 1 wherein said impedance element is a core having about it a coil of wire and is of substantially rectangular cross section and wherein said raceway is formed between said strip and a substantially vertical side of said coil.

3. A machine as set forth in claim 1 which includes a plurality of balls in said raceway.

4. A machine as set forth in claim 1 in which said tiltable structure includes a disc of electrically insulating material and wherein said element and said strip are mounted on said disc but are insulated from each other.

5. In a device for equalizing the speed of a material being passed through different sections of a machine system, an impedance element in the form of an arc, an electrically conducting strip beside said impedence element but out of electrical contact with said impedence element, said strip forming with the side of said imped- 6. A device as set forth in claim 5 wherein there is contained between the lower edge of said strip and a side of said impedence element an opening through which particles in said raceway may drop from the device. 

1. In a machine wherein a flexible material is passed at varying speeds through one section of a machine and also through another section of a machine and wherein said material forms a depending loop of said material between said sections, the improvement in said machine comprising a tiltable structure having a member which is in a position to contact the bottom side of said loop whereby to tilt said structure in one direction when the bottom of said loop is lowered and in an opposite direction when said bottom is raised, an impedance element in the form of an arc mounted on said tiltable structure, a strip of electrically conducting material beside said element, said strip being in arcuate form corresponding with the arc of said element, said strip being turned inwardly toward said element at its outer edge to form with a side of said element a raceway providing support therein for a ball but being spaced from said side of the element to form an opening through which particles in said raceway may fall from said structure, a ball of electrically conducting material in said raceway, said ball being movable to seek the lowest position in the raceway whereby to change the electrical impedance between said strip and an end of said element when said element is tilted, and being sensitive to changes in said electrical impedance for changing the speed of said material through one of said sections to bring the speed of said material in said sections more nearly into equilibrium.
 2. A machine as set forth in claim 1 wherein said impedance element is a core having about it a coil of wire and is of substantially rectangular cross section and wherein said raceway is formed between said strip and a substantially vertical side of said coil.
 3. A machine as set forth in claim 1 which includes a plurality of balls in said raceway.
 4. A machine as set forth in claim 1 in which said tiltable structure includes a disc of electrically insulating material and wherein said element and said strip are mounted on said disc but are insulated from each other.
 5. In a device for equalizing the speed of a material being passed through different sections of a machine system, an impedance element in the form of an arc, an electrically conducting strip beside said impedence element but out of electrical contact with said impedence element, said strip forming with the side of said impedence element a raceway for a ball, a ball of electrically conducting material in said raceway, and a second ball in said raceway, said balls being movable to seek the lowest position in said raceway whereby to change the electrical impedance between said strip and an end of said impedence element when said element and said strip are turned about their axes.
 6. A device as set forth in claim 5 wherein there is contained between the lower edge of said strip and a side of said impedence element an opening through which particles in said raceway may drop from the device. 